Just a quick note to let you know I have only had time for 3 short test runs. The longest was about 5 miles out and back, up and down 2 pretty good hills in each direction. Total time - about 40 minutes, probably 25-30 minutes under power with pedal assist. The highest point (also the furthest point) was probably 175-200 vertical feet above the start. I didn't notice any drop in power at the end of the ride. I decided to try hooking the batteries in parallel and charging them with the 12 v charger. It has an ammeter and after that ride it charged at 5 amps for about an hour and then it dropped back to 2 amps. I left it for another hour and turned it off. I haven't had a chance to run the batteries to a noticeable drop in power, but maybe this weekend. I'm going to start carrying a notebook and writing the variables down so I can be a little more scientific with my analysis. Also, I only have an analog multimeter at this point, but I may spring for a digital, so I can get more accurate voltage readings - jd